Explosive composition



Patented Sept. 26, 1933 EXPLO SIVE COIWPOSITION Walter 0. Holmes, Woodbury,

E. I. du Pont de Nemours N. 3., assignor to & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application July 8, 1931 Serial No. 549,564

11 Claims.

This invention relates to stabilized explosives containing nitric esters, and more particularly to dynamites containing nitroglycerin as the principal explosive.

It is the practice in the manufacture of nitroglycerin explosives, or dynamites, to incorporate with the nitroglycerin a number of other ingredients. These. other ingredients are, in general, non-explosive by themselves and are present as absorbents for nitroglycerin, as oxygen carriers, freezing point depressants, etc. While some of the ingredients present in dynamite are chemically inert, others of the ingredients may have an active chemical action, particularly as prometers of hydrolysis. It has long been recognized that nitroglycerin tends to hydrolyze more or less in the presence of acids, alkalies or soluble salts. This hydrolysis tends to a slight decomposition of the nitroglycerin, with the liberation of small amounts of acidity. This acidity has a very deleterious effect on the further behavior of the nitroglycerin. In order to neutralize the effects of any small amounts of acid formed, it has been customary to incorporate with the other ingredients of dynamite a small percentage of a substance that can combine with the acid. Such acid-neutralizing materials have been commonly termed antacids. Materials of this kind, which have been used, have included such compounds as calcium carbonate, magnesium carbonate, and zinc oxide.

While it has been customary to use inorganic antacids, such as those mentioned above, in practically all dynamites, organic materials have also been occasionally used. Diphenylamine, for example, may be mentioned as an organic material that has been used as a stabilizing agent. Many other organic compounds have likewise been suggested.

The present invention has as an object the production of a nitroglycerin explosive of improved stability. A further object of the invention is an explosive comprising a new composition of materials not heretofore proposed for this purpose.

I have found that unusual and beneficial results are obtained if a small amount of an organic ester of phosphoric acid is incorporated in the explosive composition. I have found triphenylphosphate to be a satisfactory compound for this purpose. However, other similar esters of phosphoric acid may be used, such for example, as

' tricresylphosphate, tributyl phosphate, or dibutyl phenyl phosphate.

The inorganic antacids mentioned in the foregoing are beneficial because of their properties as acid acceptors, due to their basic nature. The esters of phosphoric acid mentioned herein have also the power to fix small amounts of nitric acid, although their basic properties are very slight.

I have found that the incorporation of triphenylphosphate and other phosphoric acid esters as stabilizing materials is advantageous in all nitroglycerin explosives. However, I find their use particularly desirable in explosives of the 6 gelatinous type, since, in this case, decomposition of the nitroglycerin has particularly undesirable results.

One of the methods of determining the relative stability of explosives is to measure the volume of gas evolved under standard temperature conditions, the gas formed being due to decomposition reactions. Using such a method, triphenylphosphate wasfound to reduce the volume of gas driven off. Also explosives containing triphenylphosphate are found to stand up better on storage.

By way of illustrating my invention, the following example of an explosive composition made according to my invention is given.

Per cent Nitroglycerin 34.0 Nitrocellulose 1.0 Sodium nitrate 52.0 Wood pulp 8.0 Starch 3.0 35 Sulfur 1.6 Triphenylphosphate--- 0.4

' It is to be understood that the above example is merely illustrative of an explosive mixture containing triphenylphosphate as a stabilizing ma- 00 terial, and that the composition may vary widely, both in the kinds and amounts of ingredients used.

In the example given, I have cited nitroglycerin as the liquid explosive ingredient. If desirable, f however,-I may replace the nitroglycerin, wholly or in part, by a nitroglycol, for example, ethylene. glycol dinitrate. Also, I may substitute for a portion of the nitroglycerin any of; the wellknown freezing point depressants such as, for example, nitrated polymerized. glycerin, nltrated sugars, nitrochlorhydrins, or aromatic nitrocompounds. Similarly I may replace the sodium nitrate, wholly or in part, by other oxygen-carrying compounds such as, for example ammonium nitrate, potassium nitrate, barium nitrate, etc. While varying amounts of triphenylphosphate may be used with beneficial effects to the properties of the explosive, I prefer to use amounts not greater than 2 per cent of the explosive by weight,

phosphate gives satisfactory results.

since the use of high percentages has a tendency to decrease thesensitiveness of the explosive and to increase the cost. I prefer also to use an amount of triphenylphosphate of not less than 0.1 per cent, since smaller amounts do not give as great an improvement to the explosive as desired. I have found 0.4 per cent of triphenyl- This material may be mixed with the other solid ingredients of the dynamite previous to the absorption of the nitroglycerin, or it may be mixed with the nitroglycerin previous to the addition of the absorbents and other solid ingredients.

While I have described my invention above in detail, I wish it tobe understood that many changes may be made therein Without departing from the spirit of the invention, and that I do not intend to be limited except as indicated in the following patent claims:

I claim:

1. An explosive composition comprising a liquid organic nitric ester and an organic ester of phosphoric acid. v

2. An explosive composition comprising nitroglycerin and an organic ester of phosphoric acid.

3. An explosive composition comprising a liquid organic nitric ester and triphenylphosphate.

4. An explosive composition comprising a liquid organic nitric ester and tricresylphosphate.

5. An explosive composition comprising nitroglycerin and triphenylphosphate.

6. An explosive composition comprising nitroglycerin and tricresylphosphate.

'7. An explosive composition comprising nitroglycerin, nitrocellulose and triphenylphosphate.

8. An explosive composition comprising nitroglycerin, nitrocellulose and tricresylphosphate.

9. An explosive composition comprising nitroglycerin, nitrocellulose, one or more oxygen carrying compounds, absorbent materials for the liquid explosive, and triphenylphosphate.

10. An explosive composition comprising nitroglycerin, nitrocellulose, one or more oxygen carrying compounds, absorbent materials for the liquid explosive, and tricresylphosphate.

11. An explosive composition comprising nitroglycerin, nitrocellulose, one or more oxygen carrying compounds, absorbent materials for the liquid explosive, and an amount of triphenylphosphate between 0.1 and 2 per cent.

WALTER C. HOLMES. 

